Environmental Protection

The Grizzly, Our Greatest Wild Animal

The Development of the Feeling for Nature in the Middle Ages and Modern Times

Our National Forests

My Year In A Log Cabin

The Grizzly, Our Greatest Wild Animal

Adventures of a Young Naturalist

Practical Forestry in the Pacific Northwest

Wild Spain (España agreste)

Michigan Trees: A Handbook of the Native and Most Important Introduced Species

My Year in a Log Cabin

Getting Acquainted with the Trees

The Nakimu Caves, Glacier Dominion Park

My First Summer in the Sierra (With Original Drawings & Photographs)

Pere Marquette State Park

British Bees An Introduction into the Studies of the Natural History and Economy of the Bees Indigenous to the British Isles

A voyage to Spitzbergen

The Geology of Button Bay State Park

Cactus Forest Drive, Saguaro National Monument

Silent Wings of Freedom

Dirt and Its Secrets Revealed